Gary,
Further to my point. It really helps when one is able to identify the Beast of the Sea of Rev 13. This beast could be either ISIS or IRAN give its location. The Harlot is ISLAM as I pretty conclusively proved in other posts. With that knowledge, we are able to see who is celebrating the spiritual defeat of the church here.
Revelation 11:9
Then those from the peoples, tribes, tongues, and nations will see their dead bodies three-and-a-half days, and not allow their dead bodies to be put into graves.
These "peoples, tribes, tongues and nations" are Islamic. It is they who celebrate the spiritual defeat of the church in the above passage. Now compare to the below passage:
Revelation 17:15
Then he said to me, “The waters which you saw, where the harlot sits, are peoples, multitudes, nations, and tongues.
Thus the "waters" are Islamic peoples where the Great False religion ISLAM sits. Where "Islam sits" is where the Greek Orthodox Church used to thrive and flourish. The Christian faith or more broadly speaking, the monotheistic belief in God, is almost completely gone from the "sea."